Noble fellow pockets silver coin finally (7)
I believe the answer is:
magnate
'noble' is the definition.
(thesaurus)
'fellow pockets silver coin finally' is the wordplay.
'fellow' becomes 'mate' (I've seen this before**).
'pockets' means one lot of letters goes inside another.
'silver' becomes 'ag' (Ag is the chemical symbol for silver).
'finally' says to take the final letters.
The final letter of 'coin' is 'n'.
'ag'+'n'='agn'
'mate' going around 'agn' is 'MAGNATE'.
(Other definitions for magnate that I've seen before include "Fat cat" , "Wealthy business leader" , "Fellow with a lot of money" , "Wealthy or powerful businessman" , "Important fellow" .)